Rattling, diesel noise when in motion

[Franklin Jones]

Ok guys. Two mechanics can’t find what’s wrong, so it’s up to the internet.

When I am cruising down the road, almost always over 35mph, I get a loud rattling, exhaust, diesel sound that, when I change the RPMs, will sound like it snaps shut. When it starts, it’s pretty constant until I goose the gas and it snaps shut.

I can hear it in the cab with the windows up, and can really hear it when the windows are down and I drive by a building or something it can echo off of.

It does not do it at idle - idle sounds GREAT.

It does not do it in park, no matter the RPMs.

It really sounds like exhaust, but the best exhaust guys in town said everything checks out.

It’s also worse when the engine is warm.

It’s noisiest in the 1600 - 2000 rpm range, but can happen anywhere.

Within the last 3000 miles I had a full tune up - new plugs, New O2s, new fluids all around inc oil, trans, diffs, transfer case, and coolant. Also had both IWEs replaced.

I’ve got no codes, lots of power, but MPGs *might* be taking a hit. Only about 108k on the clock.

Any ideas?

 

[Yupster Dog]

Going off your description, i would try checking the engine, transmission mounts. it could be at a certain torque it lifts up just enough to open something, but at a higher torque everything moves together.
it could be broke but also a mechanic will undo a mount (or a heat shield another possibility) to give them a couple inches to get at something O2 sensor, drain or fill plugs ect...

 

[The Wiped Cam]

Do a test drive with both VCT solenoids disconnected.

 

[Franklin Jones]

Going off your description, i would try checking the engine, transmission mounts. it could be at a certain torque it lifts up just enough to open something, but at a higher torque everything moves together.
it could be broke but also a mechanic will undo a mount (or a heat shield another possibility) to give them a couple inches to get at something O2 sensor, drain or fill plugs ect...

The exhaust guys *did* remove a heat shield from one of the converters they said was loose, but that didn’t solve it.

Ill crawl underneath tomorrow and investigate the mounts. Just looking for wear in the bushings, or did Ford do something weird with these?

 

[Franklin Jones]

Do a test drive with both VCT solenoids disconnected.

And what am I looking for here? If the noise is gone, then the solenoids need replaced? Or will the noise be worse?

 

[JasonH]

Ok guys. Two mechanics can’t find what’s wrong, so it’s up to the internet.

When I am cruising down the road, almost always over 35mph, I get a loud rattling, exhaust, diesel sound that, when I change the RPMs, will sound like it snaps shut. When it starts, it’s pretty constant until I goose the gas and it snaps shut.

I can hear it in the cab with the windows up, and can really hear it when the windows are down and I drive by a building or something it can echo off of.

It does not do it at idle - idle sounds GREAT.

It does not do it in park, no matter the RPMs.

It really sounds like exhaust, but the best exhaust guys in town said everything checks out.

It’s also worse when the engine is warm.

It’s noisiest in the 1600 - 2000 rpm range, but can happen anywhere.

Within the last 3000 miles I had a full tune up - new plugs, New O2s, new fluids all around inc oil, trans, diffs, transfer case, and coolant. Also had both IWEs replaced.

I’ve got no codes, lots of power, but MPGs *might* be taking a hit. Only about 108k on the clock.

Any ideas?

What year is the vehicle?

 

[The Wiped Cam]

And what am I looking for here? If the noise is gone, then the solenoids need replaced? Or will the noise be worse?

Basically trying to narrow down, since you also mentioned a recent spark plug change. A badly done spark plug change can result in those noises too.

However, make 100% sure that you also don't encounter that rattling sound for a couple seconds after a cold start.

 

[Boostedbus]

How about catalytic converters being broken up on inside. Chunks rattling around until hard acceleration then the exhaust pressure pins them against the shell. Just a thought.

 

[Franklin Jones]

What year is the vehicle?

2014, 5.4 3v.
Sorry, thought that was in my sig.

 

[Franklin Jones]

Basically trying to narrow down, since you also mentioned a recent spark plug change. A badly done spark plug change can result in those noises too.

However, make 100% sure that you also don't encounter that rattling sound for a couple seconds after a cold start.

I have listened for a rattle at cold start, but haven’t heard one.

Can you elaborate more on a badly done spark plug job?
1. How do you mess up spark plugs?
2. What actually causes the noise in this case?

It didn’t start right after the plug change, and seems to be getting worse (or I’m just more annoyed by it)